The present invention relates to a method and apparatus for displacing material. More specifically, the invention relates to a method and apparatus for displacing material that utilizes a projectile that penetrates the material.
Conventional excavation techniques for removing materials or material build up, such as rock, concrete, such as found in buildings and reinforcements, deploy drills and explosives placed in drilled holes. Explosives when detonated cause a layer of the material to fracture and break apart. The resulting rubble is cleared from the excavation site and the process is repeated for a subsequent layer of material to be penetrated. Such conventional excavation techniques are slow and tedious in that several distinct and separate steps must be performed in sequence to excavate each layer of material to be removed. Moreover, mechanical drill bits wear down and break, with the required maintenance of mechanical drilling apparatus generally increasing in proportion to the hardness of the material to be drilled, causing delays and interruptions in the drilling process.
In this regard, U.S. Pat. No. 6,405,628 discloses a method and an apparatus for rapidly boring through and excavating hard materials and removal thereof without requiring the separate steps of drilling, placement of explosives, detonation of explosives, and debris removal associated with conventional excavation techniques. The disclosed method and apparatus involves the use of firing barrels to fire projectiles and an energetic slurry at the material to be excavated. While the technique disclosed in the patent is designed to provide a rapid removal of hard materials, nonetheless, the reloading of projectile and energetic slurry can slow the excavation progress, as the technique involves non-conventional gun technology.
It is known that conventional gun systems can also be utilized to break down materials by firing multiple projectiles at the material. Conventional gun systems, however, generally employ the use of rifling to improve the accuracy of the gun system. As is commonly known, the rifling of a barrel causes a projectile to spin, thereby imparting stability to the projectile. It has been found, however, that a spinning projectile does not penetrate a hard surface as well as a non-spinning projectile, particularly for those projectiles specifically designed for excavation work.
In view of the above, it would be desirable to provide a method and apparatus for rapidly removing or displacing material that could utilize conventional gun systems.